Use of catalytic converters with engines used to power automobiles are well known. These converters generally comprise a honeycomb structure positioned within an outer housing. The honeycomb structure is coated with platinum and rhodium. Exhaust gas from the engine is routed into the converter housing to the coated honeycomb structure. There, catalysis occurs, whereby carbon monoxide and hydrocarbons are oxidized to form carbon dioxide and water, and oxides of nitrogen are reduced to form nitrogen.
Catalytic converts are also used with two-cycle engines used to power watercraft. Conversion of exhaust gases from these engines is especially important because the exhaust gases therefrom are typically routed into the water. The exhaust gas may react with the water to form acids and other undesirable compounds, and may also be released from the water to the atmosphere.
A problem arises, however, with use of catalytic converters in these watercraft engines when the engine includes a engine control which includes a misfiring operational control mode. It is often common to employ an engine control in which the engine speed is controlled to correct engine abnormalities such as overheating. In these systems, when an engine abnormality is detected, one or more of the ignition elements corresponding to one or more of the combustion chambers of the engine are misfired so that incomplete combustion occurs in those chambers.
A problem associated with this incomplete combustion is that an unburned air and fuel component is exhausted from these combustion chambers to the exhaust system. The unburned fuel may foul a catalytic converter, and the risk exists that the mixture will ignite within the converter and cause serious damage thereto.
A means for preventing the fouling of a catalytic converter of a two-cycle engine having an engine control is desired.